FIELD OF THE INVENTION
This invention relates to the novel macrocyclic compounds, preparation thereof, an uranyl ion capturing agent comprising a polymer chemically bonded to a functional group in a macrocyclic compound and preparation thereof.
Recently, many efforts are being made in various fields of industry for recovering the uranyl ions (UO.sub.2.sup.+) from seawater, dam waste water, poor ore and other sources. Uranyl ions are attracting attention of the researchers as a promising source of atomic energy in these days of "oil crises", and many advanced countries are struggling with devicing a method for recovering the uranyl ions from seawater which may well be said inexhausible.
As a means for extracting the uranyl ions from seawater, there is a known method using a titanic acid adsorbent, but this method has a defect in that some of the adsorbent is lost by such as flowing out or so in use. Uranyl ions exist in seawater at a concentration of approximately 3.3 ppb in the form of a stable carbonate complex salt, so in order to extract such uranyl ions from seawater on an industrial scale, it is necessary to use an extracting agent which has ability of extracting the uranyl ions from the carbonate complex salt easily and also of selectively extracting the uranyl ions from other metal ions such as magnesium ions. In the course of the study, from said viewpoint, on the cyclic compounds having an ability to capture the metal ions, the present inventors had found that when a macrocyclic hexaketone or a polymer having such macrocyclic hexaketone as functional group is used in place of said titanic acid adsorbent, it is possible to extract the uranyl ions easily from the carbonate complex salt and to capture the uranyl ions selectively and stably too, and a patent application is filed for this finding (Japanese Patent Application No. 053025/1979).
As a result of further studies on the cyclic compounds having an ability to capture the uranyl ions, we have now succeeded in developing a new uranyl ion capturing agent which, as compared with previously proposed uranyl ion capturing agent composed of a macrocyclic hexaketone or a polymer having such macrocyclic hexaketone as functional group, is far less interfered with other metals or anions in capturing the uranyl ions and which can be also synthesized in a more simple process.